Long-term durability of response to adalimumab in Crohn's disease

Background: Adalimumab is an effective treatment for Crohn's disease (CD), but may also be associated with loss of response. Few reports provide insight into the durability of treatment of CD with adalimumab for periods longer than 12 months in clinical practice. Aims: To evaluate the long-term durability of adalimumab maintenance treatment and to identify predictive factors associated with loss of response. Methods: CD patients who initially responded to adalimumab were evaluated in a historical cohort study. Maintenance of long-term response was estimated using Kaplan-Meier analysis. Cox regression analysis was performed to identify potential predictive factors for loss of efficacy. Results: In all, 380 CD patients were included (mean age, 38 years; 52% female). Of these, 43% had ileocolic CD, 50% inflammatory CD, and 41% perianal CD. Median follow-up with adalimumab was 8 months (range, 4-75 months). The annual risk of loss of response to adalimumab was 18% per patient-year of follow-up. Twenty-eight percent of patients were anti-TNF-nai ve and 72% anti-TNF-experienced. The loss of efficacy was 8% per patient-year of follow-up in the anti-TNF-naive patients and 22% in the anti-TNF-experienced group (P < 0.01). In the multivariate analysis, the presence of extraintestinal manifestations (hazard ratio [HR] 1.7; 95% confidence interval [CI] 1.02-2.9) and previous experience with other anti-TNF agents (HR 2.5,95% CI 1.2-5.3) were associated with higher risk of loss of efficacy. Conclusions: A relevant proportion of CD patients on long-term adalimumab lost response. The risk of loss of response was higher (more than 2-fold) in anti-TNF-experienced than in anti-TNF-naive patients (22% vs. 8% per patient-year of treatment). Having extraintestinal manifestations seems to increase the risk of loss of efficacy.